Search Results (94)

Urban thermal environments, characterized by the interplay between indoor and outdoor conditions, pose growing challenges in high-density coastal cities. This study proposes a multi-scale, integrative framework that couples a satellite-derived land surface temperature (LST) analysis with microscale building performance simulations to holistically evaluate the high-density urban thermal environment in subtropical climates. The results reveal that compact, high-density morphologies reduce outdoor heat stress (UTCI) through self-shading but lead to significantly higher cooling loads, energy use intensity (EUI), and poorer daylight autonomy (DA) due to restricted ventilation and limited sky exposure. In contrast, more open, vegetation-rich forms improve ventilation and reduce indoor energy demand, yet exhibit higher UTCI values in exposed areas and increased lighting energy use in poorly oriented spaces. This study also proposes actionable design strategies, including optimal building spacing (≥15 m), façade orientation (30–60° offset from west), SVF regulation (0.4–0.6), and the integration of vertical greenery to balance solar access, ventilation, and shading. These findings offer evidence-based guidance for embedding morphological performance metrics into planning policies and building design codes. This work advances the integration of outdoor and indoor performance evaluation and supports climate-adaptive urban form design through quantitative, policy-relevant insights. Full article

This study proposes a building energy element technology system that addresses cooling loads, in response to rising average temperatures due to global warming caused by climate change. The study analyzes performance variations and energy-saving potential based on design parameters of individual element technologies, utilizing both simulation and field demonstration to derive an integrated Cooling Load Package System (CPS). The methodology comprises three key steps: (1) identifying and selecting element technologies suitable for optimal building design under subtropical climate conditions, (2) employing the building energy simulation software EnergyPlus v9.6.0 to evaluate the energy performance of each technology and establish prioritization based on energy-saving potential, and (3) conducting local climate validation through the construction of an outdoor demonstration site in northern Vietnam to assess the real-world energy-saving effectiveness of the proposed CPS. Full article

Land-based bioenergy systems are increasingly promoted for their potential to support climate change mitigation and energy security. Building on previous productivity and efficiency analyses, this study applies the MiscanFor and SalixFor models to evaluate land use energy intensity (LUEI) for Miscanthus (Miscanthus × giganteus) and willow (Salix spp.) under baseline (1961–1990) and future climate scenarios, and Business-as-Usual (B1) and Fossil Intensive (A1FI) scenarios, projected to 2060. The study also assesses the impact of biomass transport on energy use efficiency (EUE) and quantifies soil organic carbon (SOC) sequestration by Miscanthus. Under current conditions, Miscanthus exhibits a higher global mean LUEI (321 ± 179 GJ ha⁻¹) than willow (164 ± 115.6 GJ ha⁻¹) across all regions (p < 0.0001), with energy yield hotspots in tropical and subtropical regions such as South America, Sub-Saharan Africa, and Southeast Asia. Colder regions, such as Europe and Canada, show limited energy potential. By 2060, LUEI is projected to decline by 9–15% for Miscanthus and 8–13% for willow, with B1 improving energy returns in temperate zones and A1FI reducing them in the tropics. Global EUE for Miscanthus declines significantly (p < 0.0001) by 21%, from 15.73 ± 7.1 to 12.37 ± 5.2 as biomass transport distance increases from 50 km to 500 km. Mean SOC sequestration is estimated at 1.20 ± 1.46 t C ha⁻¹, with tropical hotspots reaching up to 4.57 t C ha⁻¹ and some cooler regions exhibiting net losses (–7.93 t C ha⁻¹). Climate change significantly reduces SOC gains compared to baseline (p < 0.0001), although differences between B1 and A1FI are not statistically significant. These findings highlight the importance of region-specific, climate-resilient biomass systems to optimize energy returns and carbon benefits under future climate conditions. Full article

The subtropics are affected by severe climate change, which may induce heat stress in animals. Moreover, the region is significantly seasonal; hence, mitigating climate risks and implementing climate adaptation measures are necessary. Sustainable Development Goals 1, 2, and 13 call for no poverty, zero hunger, and climate action. These are the most severe problems affecting food security in the modern world. Food security refers to a situation in which all people have physical, social, and economic access to sufficient, proper, and healthy food that satisfies their dietary requirements. Nevertheless, the projected increase in the human population implies a greater demand for employment opportunities; hence, developing countries are building more industrial areas. The burning of fossil fuels in various industries potentiates climate change and environmental pollution. It is predicted that the ecological temperature will increase by almost 2.3–4.8 °C by 2100 due to climate change. Agriculture and animal products remain vital in Africa as drivers of the economy and transformation for sustainable livelihood and development. Sheep production has long been used as a source of income and livelihood and provides jobs for people who live in rural areas. It is also sometimes used for ritual ceremonies and to pay penalties to local authorities. Nevertheless, sheep have been identified to be sensitive to heat stress, characterized by low reproductive performance, low microbiota quantities, and poor general health. There are different strategies for mitigating heat stress; however, many smallholder farmers have limited access to education and lack the financial support required to incorporate artificial shade and plant trees for shade to limit heat stress. In this review, we aim to understand the effects of environmental heat stress on sheep production and reproductive performance. Based on this review, it can be concluded that heat stress can threaten food security if not addressed, especially for farmers who depend on sheep rearing. As a result, future studies are recommended to understand different adaptation methods that can be used to mitigate the heat stress effect on sheep productivity, reproductivity, and general health. Full article

In the context of global warming, building transformation takes on a dual responsibility to be more energy-efficient and sustainable for climate change mitigation and to be more climate-resilient for occupants’ comfort. The building energy retrofitting is an urgent need due to the large amount of existing building stock. Especially in high-rise and high-density cities under a subtropical climate, like Hong Kong, existing buildings with large glazed façades face the challenges of high energy consumption and overheating risks. An advanced glazing system, namely the vacuum insulating glazing (VIG), shows the potential for effective building envelope retrofitting due to its excellent thermal insulation ability. Yet, its performance for practical applications in the subtropical region has not been investigated. To enhance the energy performance and thermal comfort of existing high-rise buildings, this study proposed a novel retrofitting approach by integrating the VIG into the existing window system as secondary glazing. Field experiments were conducted in a commercial building in Hong Kong to investigate the thermal performance of the VIG retrofit application under real-world conditions. Furthermore, the energy-saving potential and thermal comfort performance of the VIG retrofit were evaluated by building energy simulations. The experimental results indicate that the VIG retrofit can effectively stabilize the fluctuation of the inside glass surface temperature and significantly reduce the heat gain by up to 85.3%. The simulation work shows the significant energy-saving potential of the VIG retrofit in Hong Kong. For the VIG retrofit cases under different scenarios, the energy-saving potential varies from 12.5% to 29.7%. In terms of occupants’ thermal comfort, the VIG retrofit can significantly reduce the overheating risk and improve thermal satisfaction by 9.2%. Due to the thermal comfort improvement, the cooling setpoint could be reset to 1 °C higher without compromising the overall thermal comfort. The average payback period for the VIG application is 5.8 years and 8.6 years for the clear glass retrofit and the coated glass retrofit, respectively. Therefore, the VIG retrofit approach provides a promising solution for building envelope retrofits under subtropical climate conditions. It not only benefits building owners and occupants but also contributes to achieving long-term climate resilience and the carbon neutrality of urban areas. Full article

This study focuses on the nameplate of Vila D. Bosco, a modern building in Macau from the time of Portuguese rule, and looks at the types of metal materials and surface coatings used, as well as how they corrode due to the tropical marine climate affecting the building’s metal parts. The study uses different techniques, such as X-ray fluorescence spectroscopy (XRF), scanning electron microscopy/energy dispersive spectroscopy (SEM-EDS), X-ray diffraction (XRD), attenuated total internal reflectance Fourier transform infrared spectroscopy (ATR-FTIR), and cross-sectional microscopic analysis, to carefully look at the metal, corrosion products, and coating of the nameplate. The results show that (1) the nameplate matrix is a resulfurized steel with a high sulfur content (Fe up to 97.3% and S up to 1.98%), and the sulfur element is evenly distributed inside, which is one of the internal factors that induce corrosion. (2) Rust is composed of polycrystalline iron oxides such as goethite (α-FeOOH), hematite (α-Fe₂O₃), and magnetite (Fe₃O₄) and has typical characteristics of atmospheric oxidation. (3) The white and yellow-green coatings on the nameplate are oil-modified alkyd resin paints, and the color pigments are TiO₂, PbCrO₄, etc. The surface layer of the letters is protected by a polyvinyl alcohol layer. The paint application process leads to differences in the thickness of the paint in different regions, which directly affects the anti-rust performance. The study reveals the deterioration mechanism of resulfurized steel components in a subtropical polluted environment and puts forward repair suggestions that consider both material compatibility and reversibility, providing a reference for the protection practice of modern and contemporary architectural metal heritage in Macau and even in similar geographical environments. Full article

Modular green wall, or living wall (LW) system, has evolved worldwide over the past decades as a popular green building feature and a nature-based solution. Differential climatic conditions across the globe make the standardisation of practices inapplicable to local scenarios. LW projects with differing goals and preferences like aesthetic (such as plant healthiness), water-saving, and minimal plant growth require optimal combinations of plant species to achieve single or multiple goals. This exploratory study aimed to deploy empirical field LW data to optimise analytical models to support plant species selection and LW design. Plant growth performance and water demand data of 29 commonly used plant species in outdoor modular LW systems without irrigation were collected in subtropical Hong Kong for 3 weeks. The 29 species tested were grouped into five plant forms: herbaceous perennials (16 spp), succulents (2 spp), ferns (2 spp), shrubs (7 spp), and trees (2 spp). Plant species-specific plant height, LAI, plant health rating, and water absorption amount were recorded every 6 days, together with photo records. Total water demand varied widely among plant species, ranging from 52.5 to 342.5 mL in 3 weeks (equivalent to 2.5 to 16.3 mL per day). The random forest algorithm proved that the water demand of the species was a dominant predictor of plant health tendency, among other parameters. Hierarchical clustering grouped plant species with similar water demand and health rating tendencies into four groups. The health rating threshold approach identified the top-performing species that displayed a healthy appearance as a basic prerequisite, coupled with one or two optional objectives: (1) water-saving and (2) slow-growing. The comparison among the plant selection scenarios based on projected LW performance (water demand, plant health, and growth) provided sound evidence for the optimisation of LW design for sustainability. LW projects with multiple objectives inherited a multitude of multi-scalar properties; thus, the simulation of LW performance in this study demonstrated a novel data-driven approach to optimise plant species selection and planting design with minimal resource input. Full article

This paper provides a comparative analysis of green building strategies in circular cities from an architectural perspective. It focuses on Belgrade, Serbia, which has a temperate continental climate, and Podgorica, Montenegro, with a mild subtropical climate. The data were gathered through an online questionnaire disseminated among 140 architects in both cities. A five-point Likert scale was applied, and the data were analyzed using the Statistical Package for the Social Sciences (SPSS, version 23). Descriptive statistics, factor analysis, reliability testing, and group comparison methods were employed to ensure a valid, reliable, and transparent framework for processing and interpreting the research of data. By analyzing locally available materials, technologies, and climate factors, the research found that the adoption of circular economy principles does not significantly differ between the cities. This suggests that economic and policy-related factors may have a greater influence than initially expected. Additionally, there was no significant difference in the integration of greening strategies integration (p = 0.08), challenging the assumption that climate-responsive design would lead to distinct variations in urban form. However, locally available materials and technologies had a stronger impact on green building practices in Serbia (p = 0.01). The study highlights that sustainable architecture is shaped by a combination of local resources, regulatory frameworks, and socio-economic conditions rather than climate factors alone. These insights contribute to the theoretical advancement of climate-smart green building strategies in circular cities. They provide valuable guidance for practitioners and policymakers. Future research should further explore the interplay of socio-economic and regulatory influences to refine strategies for climate-responsive and circular architecture. Full article

Forests are invaluable natural resources that provide essential ecosystem services, and their carbon storage capacity is critical for climate mitigation efforts. Quantifying this capacity would require accurate estimation of forest structural attributes for deriving their aboveground biomass (AGB). Traditional field measurements, while precise, are labor-intensive and often spatially limited. Handheld Mobile Laser Scanning (HMLS) offers a rapid alternative for building forest inventories; however, its effectiveness and accuracy in diverse subtropical forests with complex canopy structure remain under-investigated. In this study, we employed both HMLS and traditional surveys within structurally complex subtropical forest plots, including old-growth forests (Fung Shui Woods) and secondary forests. These forests are characterized by dense understories with abundant shrubs and lianas, as well as high stem density, which pose challenges in Light Detection and Ranging (LiDAR) point cloud data processing. We assessed tree detection rates and extracted tree attributes, including diameter at breast height (DBH) and canopy height. Additionally, we compared tree-level and plot-level AGB estimates using allometric equations. Our findings indicate that HMLS successfully detected over 90% of trees in both forest types and precisely measured DBH (R² > 0.96), although tree height detection exhibited relatively higher uncertainty (R² > 0.35). The AGB estimates derived from HMLS were comparable to those obtained from traditional field measurements. By producing highly accurate estimates of tree attributes, HMLS demonstrates its potential as an effective and non-destructive method for rapid forest inventory and AGB estimation in subtropical forests, making it a competitive option for aiding carbon storage estimations in complex forest environments. Full article

This study conducted a within-subject study to assess sleeping environmental comfort, acceptance, and self-reported sleep quality in air-conditioned and mixed-mode ventilated bedrooms in a subtropical region during the summer. A wide thermal comfort temperature range of 22.2 °C to 28.2 °C was observed, with slightly warmer thermal sensation at higher temperatures but no significant differences in sleep quality or environmental comfort acceptance within this range. Subjects adapted to warmer sleeping conditions by choosing lighter clothing and bedding insulation. Energy simulations indicated a reduction in the percentage of nights requiring cooling from 65% to 23% by increasing the set-point temperature from 22 °C to 28 °C, resulting in a potential 95% savings in cooling energy. This study advocates for an economical and energy-efficient approach to enhance sleeping thermal comfort while reducing cooling energy usage. These findings offer valuable insights for improved residential building design and optimized cooling energy management practices, especially in light of intensified climate change and the imperative for behavioral changes to promote building sustainability. Full article

In a Brazilian subtropical climate, Wood Frame construction, valued for sustainability and thermal inertia, is being tested for compatibility with Phase Change Materials (PCMs) to improve thermal performance. This study addresses the lack of research on these technologies in Brazil and evaluates the thermal performance of a single-story Wood Frame housing envelope with and without PCM in Curitiba-PR, located in southern Brazil with Cfb climate classification. Dynamic energy simulation followed ASHRAE Standard 55-2017 criteria for occupant thermal comfort. The results indicated that integrating PCM with thermal insulation (EPS) significantly improved thermal performance, reducing the daily indoor temperature range by up to 6.4 °C and increasing comfortable hours by 20%. However, Wood Frame construction without either BioPCM or EPS proved inadequate in achieving the minimum level of thermal performance required by Brazilian standards. This underscores the importance of evaluating potential users’ thermal comfort conditions alongside the building’s overall thermal performance. It also emphasizes the need to carefully consider the level of thermal insulation in conjunction with PCM for effective design decisions. Thus, this study promotes the integration of PCM and thermal insulation to enhance thermal comfort and sustainability in Wood Frame constructions in the subtropical climate of Brazil. Full article

In the face of global warming, mitigating the urban heat island effect has become an important concern worldwide. This study applies the principle of buoyancy ventilation formed by sunlight in double skin façades (DSFs) to improve the thermal environment outside buildings by discharging heat through temperature and pressure differences. The study subject is a 15 × 30 × 40 m residential concrete building situated in a subtropical climate. The lower opening of the DSF faces the outdoor environment; heat is absorbed through this opening from the ground environment and then evacuated up to above the urban canopy layer heat island in order to cool pedestrian environments on the ground. We used numerical simulation to analyze the cooling potential of this DSF in summer daytime conditions. The results show that the DSF can successfully transport heat energy and discharge it above the urban canopy layer. Significant cooling effects were observed in both the horizontal and vertical spaces on the leeward side of the building DSF through the passage of surface heat, thereby reducing the load of indoor air conditioning. Full article

An urban canopy’s humidity significantly affects thermal comfort, public health, and building energy efficiency; however, it remains insufficiently understood. This study employed 3-year (2020–2022) fixed measurements from Guangzhou to investigate the temporal patterns of relative humidity (RH), vapor pressure (Ea), and vapor pressure deficit (VPD) across eight local climatic zones (LCZs). Clear and distinct patterns in the humidity characteristics among the LCZs were revealed on multiple timescales. The RH and VPD of each zone were higher in summer than in winter, with peak RH observed in LCZ A (83.45%) and peak VPD in LCZ 3 (13.6 hPa). Furthermore, a significant daytime urban dry island (UDI) effect in the summer and a nighttime urban moisture island (UMI) effect in the winter were observed in terms of the Ea difference between urban and rural areas. The strongest UMI occurred during winter nights in LCZ 8, with a peak intensity of 0.8 hPa, while the UDI was more frequent during summer days in LCZ 1, with a maximum value of −1.2 hPa; meanwhile, compact areas had a slightly higher frequency of UDI than open areas. Finally, the effects of the urban heat island (UHI) and wind speed (V) on UMI were analyzed. During the daytime, a weak correlation was observed between the UHI and UMI. Wind enhanced the intensity of the nighttime UMI. This research offers further insights into the canopy humidity characteristics in low-latitude subtropical cities, thereby contributing to the establishment of a universal model to quantify the differences in moisture between urban and rural areas. Full article

This study evaluates the impact of building orientation, typology, and envelope characteristics on energy efficiency and CO₂ emissions in urban dwellings in subtropical climate, with a focus on Cartagena, Colombia. North-facing dwellings consistently demonstrate superior energy performance, achieving an average efficiency increase of 4.27 ± 1.77% compared to south-facing counterparts. This trend is less pronounced near the equator due to the sun’s high zenith angle. Semi-detached homes exhibit 23.17 ± 9.83% greater energy efficiency than corner houses, attributed to reduced exterior wall exposure, which lowers energy demand and CO₂ emissions by 2.16 ± 0.74 kg CO₂/m² annually. Significant disparities in emissions are observed across socioeconomic strata; homes in strata 3 and 4 show the lowest emissions (6.69 ± 1.42 kg CO₂/m² per year), while strata 5 and 6 have the highest (10.48 ± 1.42 kg CO₂/m² per year), due to differences in construction quality and glazing ratios. Roofing materials also play a key role, with thermoacoustic (TAC) roofs reducing emissions by up to 5.80% in lower strata compared to asbestos–cement roofs. Furthermore, sandwich panels demonstrate substantial potential, achieving CO₂ emissions reductions of up to 51.6% in strata 1 and 2 south-facing median homes and a minimum saving of 9.4% in strata 5 and 6. These findings underscore the importance of integrating energy performance criteria into public housing policies, promoting construction practices that enhance sustainability and reduce greenhouse gas emissions while improving occupant comfort and property value. Full article

Naozhou Island is located in a subtropical marine monsoon climate, with frequent windy days throughout the year, which has a significant impact on the residents’ lives. The spatial form of local traditional villages has adapted to the local wind environment through long-term practical exploration. This study aims to quantitatively analyze this layout to explore the patterns of its climate adaptability, thereby providing guidance for modern village construction. The research method primarily involves using CFD software (2019) to analyze the spatial form parameters of the village, namely village scale, planar form, building density, and orientation, along with their effects on average wind speed, wind speed amplification factor, and wind field coefficient under normal and extreme wind conditions. The results show that an appropriate planar form can enhance the wind adaptability of the village, while village scale and building density significantly affect the wind environment. However, the orientation of the village does not have a significant impact on wind field changes due to the discontinuity of the street system. These patterns of wind adaptability can assist in the planning and design of future coastal villages to enhance the wind environment regulation and disaster resilience of island villages. Full article